Subscribed for this build!

 

Thanks for coming by, always good to have someone else with some maggie experience.

 

Why the Livernois rocker stands? The stock stands have made a ton of power with good valve control on any of the normal springs. Id just use the stock cam bolts and retainer bolts. Clean em up and use some loctite on them unless you just want ARP bolts.

I do need to get me one of those wedge tensioners though, just seems like a good idea. I think youre on the right track for the blower grind, maybe a few degrees smaller on both sides and a little narrower on the LSA. Pat speced a 214/230 115 for my maggied LQ4, got to remember you need to keep plenty of tq when out of boost too so your mileage doesnt tank. Its been my experience it doesnt take much duration to kill the power down low of a 5.3.

 

That was something I had in mind when I was deciding on the N/A combo, and thought the idea might carry over to the FI combo since I was upgrading to dual springs. On everything I've ever built or worked on, I've always tried to stress rock-solid valvetrain stability. But I'm also not going to be revving the **** out of this motor, and I'm not really going to have crazy-high spring pressures either, so I may decide the money could be better spent on either fuelling or into the driveline.


Ya nothing's set in stone here either, it's sometimes hard to keep the size of the engine in perspective. I've got all these ideas for what will make big power, but I still have to remember the engine's pretty small to begin with.

 

Nothing really new to report, thought I might have heard about the maggie on friday, but I guess it'll ship out this week.

Here's a couple more pics of some parts just to keep you guys interested:

90mm LS3 throttle body compared to stock 87mm:

Front


Back


GM rockers with Comp trunion-bearing upgrade and ARP bolt:

 

As soon as you start making some decent power, that Gibson muffler's gonna start hissing. I'd recommend a straight-through muffler to avoid the restriction. The Gibson is really not a performance muffler.

 

If a 207/220 .571 .578 118.5 cam make almost 600rwhp TVS boost only on a 5.3 I dont really see the need for such a "big" cam...

Years ago when I had a 5.3 in my truck there wasnt much info(2005) on camming these trucks much less a heavy extended cab Z71 and I went too big(IMO) with a 222/224 112 and it really sucked when you werent on the go pedal. Driveability was fine but cruising down the highway the TC constantly had to unlock. Never really checked mileage to be honest since I didnt run it for long(swapped it for a 418 stroker lol) but I cant imagine it was anything great since the TC had to be unlocked so much to get to where it made enough power to putt down the road. It was fun when you were off in it though.

 

Agreed, it's something I'm going to give consideration to. Might take the muffler off and go straight-piped with the 3" single tubing for a while until I figure out what to do. Thinking of a 3.5" with a straight through muffler, or 4" if I think there's any benefit. I'll change my post above of the parts list to include these plans.

I'm considering a few different approaches to the cam design. I will say that I like the idea behind Geoff's lobes, and feel better with them than an X-ER cam like LPE's. But I'm also cognizant of the fact that duration lengths that work well on 6.2L and above might not necessarily provide the same gains on a 5.3 with smaller runners, ports, valves and cylinder bores. I'm going to do some thinking about where a PD supercharger likes to have the valve events, talk with Geoff and maybe a couple other guys I know and see what I can come up with to suit the 5.3.

I'm not saying this is the end all to the camshaft debate for all 5.3, but I know on trey's truck, which is pretty much identical to my setup, except for a few things like trans and 4wd, patg speced him a 218/226 I think, which isn't too far from what I've theoretically picked. Again, I'm not saying that's proof the 5.3 needs more duration, just using it as a reference point to what someone "in the know" would also think would work well with a 5.3 in a four door bus. I have no doubt the smaller duration cam like LPE's will make great power and tq, and so will one with marginally higher numbers, I'd love to see dyno graphs overlaid to evaluate both cams' power curves.

Also, if this engine does unfortunately fail, or I get tired of it, I will be going bigger, so in the back of my mind I have a plan of futureproofing it, but I'm not going to just blindly pick a cam for a 400+cubic inch engine, just to stick it in a much smaller one for an indeterminate amount of time. There's a lot of thinking to go into this, and I'm also an over-analytical type, so I'm sure I'll pull a few hairs out before all is said and done haha.

 

Got confirmation that the maggie shipped out this week and should be in next week.

 

I ordered the 1 7/8" AR Headers last night, and I'm getting them to put a 3.5" Y-pipe on it so I can run a 3.5" exhaust, which brings me to my question to you guys. I'm going to dump the exhaust before the axle, so I'm really only stuck for getting an extension pipe for the Y to the muffler. I think my only options for a 3.5" exhaust are to find a system off a late model 6.2 truck (probably big $), find some kit that comes with a 3.5 (I think MBRP has one) or going custom.

I've been looking around online at stainless tubing, and making some drawings to get a rough idea of what I need. I won't be able to get under a truck till tonight or this weekend, so my question to you guys is, can you run a straight pipe from the Y-pipe back, maybe about 4-5 feet? Or does there need to be some offset to it? I think the 3" cat back I have on there now has a little offset to it, but that might be to center the SI/DO muffler. I'm planning on going with a SI/SO muffler, so should I run into any clearance problems, you think?